http://polgraw.camk.edu.pl/tags/neutron-stars/ Neutron Stars - Tag - Virgo-Polgraw : Grawitational Waves Hugo -- gohugo.ioenMon, 16 Dec 2024 00:00:00 +0000 http://polgraw.camk.edu.pl/posts/2024-12-16/ Mon, 16 Dec 2024 00:00:00 +0000 polgraw http://polgraw.camk.edu.pl/posts/2024-12-16/ A member of our group from Copernicus Astronomical Center PAN, Sudhagar Suyamprakasam got a Preludium NCN grant for a project: “Through the lens: discovering continuous gravitational waves amplified by microlensing”. Non-symmetric rotating neutron stars are prospective sources of quasi-monochromatic (long duration, continuous) gravitational waves. They are yet to be detected as their intrinsic gravitational-wave amplitude is smaller than transient gravitational waves emitted by compact binary systems inspirals of neutron stars and black holes, now routinely detected by the LIGO-Virgo-KAGRA Collaboration network of detectors.]]> http://polgraw.camk.edu.pl/posts/2024-04-08/ Mon, 08 Apr 2024 00:00:00 +0000 polgraw http://polgraw.camk.edu.pl/posts/2024-04-08/ In May 2023, shortly after the start of the fourth LIGO-Virgo-KAGRA observing run, the LIGO Livingston detector observed a gravitational-wave signal from the collision of what is most likely a neutron star with a compact object that is 2.5 to 4.5 times the mass of our Sun. Neutron stars and black holes are both compact objects, the dense remnants of massive stellar explosions. What makes this signal, called GW230529, intriguing is the mass of the heavier object.]]> http://polgraw.camk.edu.pl/posts/2024-04-05/ Fri, 05 Apr 2024 00:00:00 +0000 polgraw http://polgraw.camk.edu.pl/posts/2024-04-05/ Next week, the LIGO and Virgo detectors will resume their observing campaigns, which promise to collect more than 200 gravitational-wave events by the end of this current observing run (O4). Astronomers also hope that new multi-messenger events will be detected. Multi-messenger events are those observed both in gravitational and electromagnetic waves, and can be further followed up by other telescopes. The LIGO-Virgo-KAGRA Collaboration will begin the second part of its fourth observing run (O4b) on April 10th.]]> http://polgraw.camk.edu.pl/posts/2022-01-14/ Fri, 14 Jan 2022 00:00:00 +0000 polgraw http://polgraw.camk.edu.pl/posts/2022-01-14/ The LIGO-Virgo-KAGRA collaboration has published the results of the search for continuous gravitational waves in the data from the entire O3 observational campaign. It is expected that such waves can be emitted by e.g. axially asymmetric neutron stars, but their amplitude is much smaller than the regularly observed, short-term signals emitted during black hole mergers. For this reason, they have not been observed so far. In this publication, we present the results of four independent methods obtained by various research groups that carried out the so-called blind searches in a wide range of parameters: all sky, frequency range from 10 to 2048 Hz and rate of frequency change from $-10^{- 8}$ to $10^{- 9}$ Hz / s.]]> http://polgraw.camk.edu.pl/posts/2021-06-29/ Tue, 29 Jun 2021 00:00:00 +0000 polgraw http://polgraw.camk.edu.pl/posts/2021-06-29/ The Virgo, LIGO and KAGRA scientific collaborations today announced the first observation ever of binary systems consisting of a neutron star (NS) and a black hole (BH). This was made possible by the detection, in January 2020, of gravitational signals (nicknamed GW200105 and GW200115 from the dates of their detection) emitted by two systems, in which a black hole and a neutron star, rotating around each other, merged into a single compact object.]]> http://polgraw.camk.edu.pl/posts/2020-10-28/ Wed, 28 Oct 2020 00:00:00 +0000 polgraw http://polgraw.camk.edu.pl/posts/2020-10-28/ The classification and definitive analysis of the 39 events detected by Virgo and LIGO in the third observation period (which ran from April to October 2019) was published today on the ArXiv online archive. Most of these are black hole mergers, the characteristics of which, however, question some established astrophysical models and open up new scenarios. A likely merger of neutron stars and two probable ‘mixed’ neutron star-black hole systems were also detected in the same period.]]> http://polgraw.camk.edu.pl/posts/2020-01-06/ Mon, 06 Jan 2020 00:00:00 +0000 polgraw http://polgraw.camk.edu.pl/posts/2020-01-06/ On April the 25th, 2019, the network of gravitational-wave (GW) detectors formed by the European Advanced Virgo, in Italy, and the two Advanced LIGO, in the US, detected a signal, named GW190425. This is the second observation of a gravitational-wave signal consistent with the merger of a binary-neutron-star system after GW170817. GW190425 was detected at 08:18:05 UTC; about 40 minutes later the LIGO Scientific Collaboration and the Virgo Collaboration sent an alert to trigger follow-up telescope observations.]]> http://polgraw.camk.edu.pl/posts/2018-12-03/ Mon, 03 Dec 2018 00:00:00 +0000 polgraw http://polgraw.camk.edu.pl/posts/2018-12-03/ The LIGO and Virgo Collaborations present new results from searches for coalescing cosmic objects. The LIGO and/or Virgo interferometers have now confidently detected gravitational waves from a total of 10 stellar-mass binary black hole mergers and one merger of neutron stars, which are the dense, spherical remains of stellar explosions. Seven of these events had been reported before, while four of the black hole detections are newly announced. From September 12, 2015, to January 19, 2016, during the first LIGO observing run since undergoing upgrades in a program called Advanced LIGO, gravitational waves from three binary black hole mergers were detected.]]> http://polgraw.camk.edu.pl/posts/2017-10-16/ Mon, 16 Oct 2017 00:00:00 +0000 polgraw http://polgraw.camk.edu.pl/posts/2017-10-16/ Discovery marks first cosmic event observed in both gravitational waves and light. For the first time, scientists have directly detected gravitational waves — ripples in space and time — in addition to light from the spectacular collision of two neutron stars. This marks the first time that a cosmic event has been viewed in both gravitational waves and light. The discovery was made using the U.S.-based Laser Interferometer Gravitational-Wave Observatory (LIGO); the Europe-based Virgo detector; and some 70 ground- and space-based observatories.]]> http://polgraw.camk.edu.pl/posts/2017-09-27/ Wed, 27 Sep 2017 00:00:00 +0000 polgraw http://polgraw.camk.edu.pl/posts/2017-09-27/ The Virgo collaboration and the LIGO Scientific Collaboration report the three-detector observation of gravitational waves. This result highlights the scientific potential of a global network of gravitational wave detectors, by delivering a better localization of the source and historically first time when the polarizations of gravitational waves have been assessed.The three-detector observation was made on August 14, 2017 at 10:30:43 UTC. The detected gravitational waves were emitted during the final moments of the merger of two black holes with masses about 31 and 25 times the mass of the Sun and located about 1.]]>